Mitigating the Uncanny Valley Effect in Hyper-Realistic Robots: A Student-Centered Study on LLM-Driven Conversations
Hangyeol Kang, Thiago Freitas dos Santos, Maher Ben Moussa, Nadia Magnenat-Thalmann
TL;DR
The paper addresses the uncanny valley barrier facing hyper-realistic social robots and tests whether LLM-driven dialogue can reduce eeriness and improve engagement. Using Nadine, with a simplified SoR-ReAct architecture and LangGraph modules (router, retriever, web search, generator) and an LLM (gpt-4o-mini) plus a Chroma vectorstore, the study delivers context-aware conversations. In a one-on-one study with 68 university participants, pre- and post-interaction surveys measured creepiness, pleasantness, approachability, naturalness, and interestingness; regression analyses identified naturalness and interestingness as key predictors of willingness to continue, while human-likeness was not. The findings suggest design guidance that prioritizes fluid, engaging dialogue over purely human-like mimicry, highlighting the practical potential of LLMs to bridge the uncanny valley in real-world social robotics.
Abstract
The uncanny valley effect poses a significant challenge in the development and acceptance of hyper-realistic social robots. This study investigates whether advanced conversational capabilities powered by large language models (LLMs) can mitigate this effect in highly anthropomorphic robots. We conducted a user study with 80 participants interacting with Nadine, a hyper-realistic humanoid robot equipped with LLM-driven communication skills. Through pre- and post-interaction surveys, we assessed changes in perceptions of uncanniness, conversational quality, and overall user experience. Our findings reveal that LLM-enhanced interactions significantly reduce feelings of eeriness while fostering more natural and engaging conversations. Additionally, we identify key factors influencing user acceptance, including conversational naturalness, human-likeness, and interestingness. Based on these insights, we propose design recommendations to enhance the appeal and acceptability of hyper-realistic robots in social contexts. This research contributes to the growing field of human-robot interaction by offering empirical evidence on the potential of LLMs to bridge the uncanny valley, with implications for the future development of social robots.
